Cultural adaptation and validation of the Persian version of the Disabilities of the Arm, Shoulder and Hand (DASH) outcome measure

Objective: To translate and validate the Persian version of the Disabilities of the Arm, Shoulder and Hand (DASH) outcome measure (Persian DASH). Design: Cultural translation and psychometric testing. Setting: Outpatient departments of orthopaedics surgery, primary care settings, rehabilitation medicine and physical therapy. Subjects: Two hundred and seventy-one consecutive Persian-speaking patients with upper extremity disorders including subacromial impingement syndrome, rotator cuff disease, epicondylitis, ulnar nerve entrapment, bursitis, instability, carpal tunnel syndrome, tenosynovitis and adhesive capsulitis. Methods: The translation and cultural adaptation of the original questionnaire was carried out in accordance with published guidelines. The participants were asked to complete a questionnaire booklet including the Persian DASH, the Short Form General Health Survey (SF-36) and a visual analogue scale WAS) of pain. In addition, 31 randomly selected patients were asked to complete the questionnaire 48 hours later for the second time. Results: Cronbach's alpha coefficient for the Persian DASH was 0.96. The Persian DASH showed excellent test-retest reliability with intraclass correlation coefficient equal to 0.82 (P < 0.01). The correlation between the Persian DASH and the functional scales of the Iranian SF-36 showed desirable results indicating a good convergent validity (Pearson's coefficients ranged from -0.25 to -0.72; P < 0.001). The correlation between the Persian DASH and the visual analogue scale was 0.52 (P < 0.01). Conclusions: The Persian DASH is a reliable and valid instrument to measure functional status in Persian-speaking patients with upper extremity disorders in Iran. It is simple and easy to use and now can be applied in clinical settings and future outcome studies in Iran and other Persia n-speaking communities.